About Breast Cancer
Who’s at risk?
The exact causes of breast cancer are not known. However, studies show that the risk of breast cancer increases as a woman gets older. This disease is very uncommon in women under the age of 35. Most breast cancers occur in women over the age of 50, and the risk is especially high for women over age 60. Also, breast cancer occurs more often in white women than African American or Asian women.
Research has shown that the following conditions increase a woman’s chances of getting breast cancer:
Personal history of breast cancer
Women who have had breast cancer face an increased risk of getting breast cancer in their other breast.
Family history
A woman’s risk for developing breast cancer increases if her mother, sister, or daughter had breast cancer, especially at a young age.
Certain breast changes
Having a diagnosis of atypical hyperplasia or lobular carcinoma in situ (LCIS) may increase a woman’s risk for developing cancer.
Genetic alterations
Changes in certain genes (BRCA1, BRCA2, and others) increase the risk of breast cancer. In families in which many women have had the disease, gene testing can sometimes show the presence of specific genetic changes that increase the risk of breast cancer. Doctors may suggest ways to try to delay or prevent breast cancer, or to improve the detection of this disease in women who have these changes in their genes. For more information about gene testing, read the “Causes and Prevention” section under “The Promise of Cancer Research.”
Other factors associated with an increased risk for breast cancer include:
Estrogen
Evidence suggests that the longer a woman is exposed to estrogen (estrogen made by the body, taken as a drug, or delivered by a patch), the more likely she is to develop breast cancer. For example, the risk is somewhat increased among women who began menstruation at an early age (before age 12), experienced menopause late (after age 55), never had children, or took hormone replacement therapy for long periods of time. Each of these factors increases the amount of time a woman’s body is exposed to estrogen.
DES (diethylstilbestrol) is a synthetic form of estrogen that was used between the early 1940s and 1971. Women who took DES during pregnancy to prevent certain complications are at a slightly higher risk for breast cancer. This does not appear to be the case for their daughters who were exposed to DES before birth. However, more studies are needed as these daughters enter the age range when breast cancer is more common.
Late childbearing
Women who have their first child late (after about age 30) have a greater chance of developing breast cancer than women who have a child at a younger age.
Breast density
Breasts that have a high proportion of lobular and ductal tissue appear dense on mammograms. Breast cancers nearly always develop in lobular or ductal tissue (not fatty tissue). That’s why cancer is more likely to occur in breasts that have a lot of lobular and ductal tissue (that is, dense tissue) than in breasts with a lot of fatty tissue. In addition, when breasts are dense, it is more difficult for doctors to see abnormal areas on a mammogram.
Radiation therapy
Women whose breasts were exposed to radiation during radiation therapy before age 30, especially those who were treated with radiation for Hodgkin’s disease, are at an increased risk for developing breast cancer. Studies show that the younger a woman was when she received her treatment, the higher her risk for developing breast cancer later in life.
Alcohol
Some studies suggest a slightly higher risk of breast cancer among women who drink alcohol.
Most women who develop breast cancer have none of the risk factors listed above, other than the risk that comes with growing older. Scientists are conducting research into the causes of breast cancer to learn more about risk factors and ways of preventing this disease.
Detecting Breast Cancer
Women should talk with their doctor about factors that can increase their chance of getting breast cancer. Women of any age who are at higher risk for developing this disease should ask their doctor when to start and how often to be checked for breast cancer. Breast cancer screening has been shown to decrease the risk of dying from breast cancer.
Women can take an active part in the early detection of breast cancer by having regularly scheduled screening mammograms and clinical breast exams (breast exams performed by health professionals). Some women also perform breast self-exams.
A screening mammogram is the best tool available for finding breast cancer early, before symptoms appear. A mammogram is a special kind of x-ray. Screening mammograms are used to look for breast changes in women who have no signs of breast cancer.
Mammograms can often detect a breast lump before it can be felt. Also, a mammogram can show small deposits of calcium in the breast. Although most calcium deposits are benign, a cluster of very tiny specks of calcium (called microcalcifications) may be an early sign of cancer.
If an area of the breast looks suspicious on the screening mammogram, additional (diagnostic) mammograms may be needed. Depending on the results, the doctor may advise the woman to have a biopsy.
Although mammograms are the best way to find breast abnormalities early, they do have some limitations. A mammogram may miss some cancers that are present (false negative) or may find things that turn out not to be cancer (false positive). And detecting a tumor early does not guarantee that a woman’s life will be saved. Some fast-growing breast cancers may already have spread to other parts of the body before being detected.
Nevertheless, studies show that mammograms reduce the risk of dying from breast cancer. Most doctors recommend that women in their forties and older have mammograms regularly, every 1 to 2 years.
Some women perform monthly breast self-exams to check for any changes in their breasts. When doing a breast self-exam, it’s important to remember that each woman’s breasts are different, and that changes can occur because of aging, the menstrual cycle, pregnancy, menopause, or taking birth control pills or other hormones. It is normal for the breasts to feel a little lumpy and uneven. Also, it is common for a woman’s breasts to be swollen and tender right before or during her menstrual period. Women in their forties and older should be aware that a monthly breast self-exam is not a substitute for regularly scheduled screening mammograms and clinical breast exams by a health professional.
Diagnosing Breast Cancer
To help find the cause of any sign or symptom, a doctor does a careful physical exam and asks about personal and family medical history. In addition, the doctor may do one or more breast exams:
Clinical breast exam
The doctor can tell a lot about a lump by carefully feeling it and the tissue around it. Benign lumps often feel different from cancerous ones. The doctor can examine the size and texture of the lump and determine whether the lump moves easily.
Mammography
X-rays of the breast can give the doctor important information about a breast lump.
Ultrasonography
Using high-frequency sound waves, ultrasonography can often show whether a lump is a fluid-filled cyst (not cancer) or a solid mass (which may or may not be cancer). This exam may be used along with mammography.
Based on these exams, the doctor may decide that no further tests are needed and no treatment is necessary. In such cases, the doctor may need to check the woman regularly to watch for any changes.
Biopsy
Often, fluid or tissue must be removed from the breast so the doctor can make a diagnosis. A woman’s doctor may refer her for further evaluation to a surgeon or other health care professional who has experience with breast diseases. These doctors may perform:
Fine-needle aspiration
A thin needle is used to remove fluid and/or cells from a breast lump. If the fluid is clear, it may not need to be checked by a lab.
Needle biopsy
Using special techniques, tissue can be removed with a needle from an area that looks suspicious on a mammogram but cannot be felt. Tissue removed in a needle biopsy goes to a lab to be checked by a pathologist for cancer cells.
Surgical biopsy
In an incisional biopsy, the surgeon cuts out a sample of a lump or suspicious area. In an excisional biopsy, the surgeon removes all of a lump or suspicious area and an area of healthy tissue around the edges. A pathologist then examines the tissue under a microscope to check for cancer cells.
When a woman needs a biopsy, these are some questions she may want to ask her doctor:
What type of biopsy will I have? Why?
How long will it take? Will I be awake? Will it hurt?
How soon will I know the results?
If I do have cancer, who will talk with me about treatment? When?
When Cancer Is Found
The most common type of breast cancer is ductal carcinoma. It begins in the lining of the ducts. Another type, called lobular carcinoma, arises in the lobules. When cancer is found, the pathologist can tell what kind of cancer it is (whether it began in a duct or a lobule) and whether it is invasive (has invaded nearby tissues in the breast).
Special lab tests of the tissue help the doctor learn more about the cancer. For example, hormone receptor tests (estrogen and progesterone receptor tests) can help determine whether hormones help the cancer to grow. If test results show that hormones do affect the cancer’s growth (a positive test result), the cancer is likely to respond to hormonal therapy. This therapy deprives the cancer cells of estrogen. More information about hormonal therapy can be found in the “Planning Treatment” section.
Other tests are sometimes done to help the doctor predict whether the cancer is likely to progress. For example, the doctor may order x-rays and lab tests. Sometimes a sample of breast tissue is checked for a gene (the human epidermal growth factor receptor-2 or HER-2 gene) that is associated with a higher risk that the breast cancer will come back. The doctor may also order special exams of the bones, liver, or lungs because breast cancer may spread to these areas.
If the diagnosis is breast cancer, a woman may want to ask these questions:
What kind of breast cancer do I have?
What did the hormone receptor test show? What other lab tests were done on the tumor tissue, and what did they show?
How will you determine whether the disease has spread?
How will this information help in deciding what type of treatment or further tests will be best for me?
Planning Treatment
Many women with breast cancer want to take an active part in decisions about their medical care. They want to learn all they can about their disease and their treatment choices. However, the shock and stress that people often feel after a diagnosis of cancer can make it hard for them to think of everything they want to ask the doctor. Often it is helpful to prepare a list of questions in advance. To help remember what the doctor says, patients may take notes or ask whether they may use a tape recorder. Some people also want to have a family member or friend with them when they talk to the doctor–to take part in the discussion, to take notes, or just to listen.
The patient’s doctor may refer her to doctors who specialize in treating cancer, or she may ask for a referral. Treatment generally begins within a few weeks after the diagnosis. There will be time for the woman to talk with the doctor about her treatment choices, to get a second opinion, and to prepare herself and her loved ones.
Other Sources of Information
National Alliance of Breast Cancer Organizations
Y-Me National Breast Cancer Organization